Portable folding chair with adjustable legs

ABSTRACT

A folding quad-style chair has a folding frame including four legs each having a leg tube, and a fabric seating section attached to the frame. An extension is telescopically extendable from each leg tube. A locking device is provided with each extension for releasably locking each extension into a fixed position. The locking device may be designed as a plurality of spaced apart holes and with the locking device including a spring urging a locking pin into one of the holes. A foot plate may be pivotally attached to a lower end of each extension. Since the length of each leg can be individually adjusted, the chair may be configured to provide a level seating surface even on a hillside, incline, or other sloped or irregular surface. All four legs may be fully extended to provide an elevated seating surface.

BACKGROUND OF THE INVENTION

Portable folding chairs have become increasingly popular for use at thebeach and parks, at sporting events, for picnics, camping, and similaruses. Many of these chairs are lightweight and fold into a compact size,with the folded chair conveniently carried in a carrying bag. Theso-called quad chair design has been in widespread use for severalyears. The quad chair has a frame typically formed from diagonal polespivotally attached to each other at the front, back, left and rightsides of the frame. This allows the quad chair frame to fold and unfoldboth in the front to back direction and in the side to side direction.As a result, when folded, the quad chair is highly compact.

Although quad chairs as a whole offer many advantages, a typically quadhas four fixed-length legs. Consequently, the height of the seatingsurface is fixed, making the chair not well adapted for seating at a baror cocktail tables, or for other uses where a higher seating surface isneeded. Quad chair legs are made all the same length, so that the chairsits level on a flat surface. When used on an inclined surface, theentire chair is necessarily inclined, providing a seating surface thatmay be tilted too far forward or back. Accordingly, engineeringchallenges remain in providing a reclining quad chair better designedfor a wider range of uses.

Other and further objects and advantages will become apparent from thefollowing detailed description, which shows one embodiment of theinvention. It will be apparent though to persons skilled in the art thatvarious other equivalent embodiments may of course be derived within thescope of the invention.

SUMMARY OF THE INVENTION

A folding quad-style chair has a folding frame including four legs eachhaving a leg tube, and a fabric seating section attached to the frame.An extension is telescopically extendable from each leg tube. A lockingdevice releasably locks each extension into a fixed position. Thelocking device may be designed as a plurality of spaced apart holes andwith the locking device including a spring urging a locking pin into oneof the holes. A foot plate may be pivotally attached to a lower end ofeach extension. Since the length of each leg can be individuallyadjusted, the chair may be configured to provide a level seating surfaceeven on a hillside, incline, or other sloped or irregular surface. Allfour legs may be fully extended to provide an elevated seating surface.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, the same element number indicates the same element ineach of the views.

FIG. 1 is a perspective view of a new quad-type chair.

FIG. 2 is a perspective view of the frame of the chair shown in FIG. 1,with the frame in a fully open or erected position, and with the frontlegs extended further than the back legs.

FIG. 3 is an enlarged perspective view detail of one of the fittingsshown in FIG. 2.

FIG. 4 is an enlarged perspective view detail of the feet shown in FIG.1.

FIG. 5 is a perspective view of the frame of the chair shown in FIG. 1,with the front legs and the rear legs fully retracted.

FIG. 6 is a perspective view of the frame of the chair shown in FIG. 1,with the front legs and the rear legs fully extended.

DETAILED DESCRIPTION OF THE DRAWINGS

As shown in FIG. 1, a portable, foldable and reclining chair 10 hasflexible material or fabric 14 attached to and/or supported on a frame12. The material 14 may be a fabric such as polyester or other syntheticor natural material. The material 14 has a seat section 20 and a backrest section 22 ordinarily provided together as a single piece, butoptionally provided as two separate pieces. Typically the chair 10 alsohas arm rests 18 of the same material. The frame 12 may be symmetricalabout the front to back centerline. Consequently, the frame elements onthe left side may be mirror images of the elements on the right side.Except as described below, the chair 10 may be may be similar or thesame as a standard quad chair, as described for example in U.S. Pat.Nos. 6,926,355 and 8,091,962, and U.S. patent application Ser. No.13/718,616, each incorporated herein by reference.

As shown in FIG. 2, the length of each of the four legs of the chair 10may be individually adjusted. FIGS. 2-6 show the frame 12 alone withoutfabric 14, for purpose of illustration. In FIG. 2, the front legs areextended out further than the rear legs, so that with the front legsresting on a first ground surface LL1, and the rear legs resting on asecond ground surface LL2 above LL1, the chair 10 is in a levelposition. This allows the chair 10 to be comfortably positioned and usede.g., on a hillside or other uneven surfaces. In the same way, the chair10 may be set up on bleachers, stadium benches, or other structures orsurfaces, to provide more comfortable seating.

FIG. 5 shows the chair 10 with all four legs fully retracted, so thatthe chair 10 is configured and has the same seat height as aconventional quad chair. FIG. 6 shows the chair 10 with all four legsfully extended. This raises the seat height to a position better suitedfor use at raised surfaces, such as bars, cocktail tables, beach orstadium railings, etc. With the legs fully extended as shown in FIG. 6,the seated user is also closer to eye level with standing persons, whichmay be advantageous for use at trade shows, sports events, etc.

The legs of the chair 10 may be made extendible in various differentways. Generally these include use of a telescoping leg element on eachof the four legs, for example via a leg extension 50 telescoping into orover a leg tube 26, as shown in FIGS. 3 and 4. In this example a fitting40 is rigidly attached onto or adjacent to the lower end of the leg tube26. The cross tubes 28 may be pivotally attached to clevis plates 46 onthe fitting 40 via cross tube pins 48. The fitting 40 may be molded ofhigh strength plastic or other materials.

As shown in FIG. 3, the extension 50 includes a series of spaced apartposition holes 52. The extension 50 may have a non-round cross section,to allow the extension 50 to telescopically slide into and out of acorrespondingly shaped opening in the fitting 40, without rotating. Thiskeeps the position holes 52 at a fixed orientation relative to thefitting 40. In the example of FIG. 3, a D-shaped extension is shown,with the position holes 52 in the flat surface of the extension. Otherextension shapes such as triangular, square, hexagonal, etc. may beused, including various other regular or irregular polygons. Typicallythe leg tube 26 is round and the upper opening in the fitting 40 iscorrespondingly round, to accept and attach to the bottom end of the legtube 26. The lower opening in the fitting 40, however, is made with across-sectional shape matching the extension 50.

As shown in FIGS. 3 and 4, the extension 50 may be moved to a desiredposition and then securely locked in place via a lock pin 42 extendingthrough a pin block or surface 44 on the fitting 40. The lock pin 42 maybe biased inwardly by a spring 54. The spring 54 positively holds theinner end of the lock pin 42 into engagement with the selected positionhole 52. The extension 50 may be moved to a different position bypulling and holding the lock pin 42 out while sliding the extension tothe new desired position, and then releasing the lock pin 42. The lockpin 42 may be provided with a knob, T-handle, or other grasping surface.Other forms of locking devices may also be used, including pipe clamps,friction clamps; cam and wedge devices, and pins extending through theextensions. The fittings and extensions may alternatively use selflocking or anti-back driving dual, tri, or quad lead screw threads.

Referring to FIG. 4, a foot 60 may have a collar 62 attached onto thebottom end of the extension 50, on each of the four legs. A foot plate68 may be pivotally attached to the collar 62 via a pin 64 extendingthrough clevis plates 68 on the foot plate 68. This allows the foot 60to pivot on a lateral (side to side) axis generally parallel to thefront edge of the seat section 20, so that the feet 60 will rest flat onan inclined (uphill/downhill) surface. Some designs may optionallyinclude a foot pivotal about the lateral axis and also about alongitudinal (front to back) axis, by including a second pivot pin shownin dotted lines 66. In this design the pins 64 and 66 form a U-jointthat allows the foot to rest flat on a surface also having lateralincline or slant.

Thus, a novel chair has been shown and described. Various changes andsubstitutions may of course be made without departing from the spiritand scope of the invention. The invention, therefore, should not belimited except by the following claims and their equivalents.

1. A folding chair, comprising: a folding frame including four legtubes; fabric including a seating section attached to the frame; anextension telescopically extendable from each leg tube; and a lockingdevice associated with each extension for releasably locking eachextension into a fixed position.
 2. The chair of claim 1 furthercomprising a foot plate pivotally attached to a lower end of eachextension.
 3. The chair of claim 1 each extension comprising a pluralityof spaced apart holes and with the locking device including a springurging a locking pin into one of the holes.
 4. The chair of claim 1 witheach extension having a non-round cross sectional shape.
 5. The chair ofclaim 4 further including with lower end of each leg tube extending intoan upper opening of a fitting, and with the fitting having a loweropening with a shape substantially matching the shape of the extension.6. The chair of claim 1 with the extension having a length between 40%and 95% of the length of the leg tube.
 7. The chair of claim 4 with thefitting further comprising first and second sets of clevis plates, afirst cross tube pin extending between the first set of clevis plates topivotally attach a lower end of a first cross tube to the fitting, and asecond cross tube pin extending between the second set of clevis platesto pivotally attach a second cross tube to the fitting.
 8. The chair ofclaim 1 with the extension having a D-shaped cross section.
 9. A foldingchair, comprising: a folding frame having four legs, with each legincluding a leg tube; fabric including a seating section attached to theframe; an extension telescopically extendable into and out of each legtube; a fitting rigidly attached to a lower end of each leg tube andhaving a lower opening with a shape substantially matching the shape ofthe extension; a foot plate pivotally attached to a lower end of eachextension; and a locking device on each fitting, with each extensionlocked in a fixed position when the locking device is in a lockposition, and with each extension telescopically movable into or out ofthe leg tube when the locking device is in a release position.
 10. Thechair of claim 9 with each extension having a non-round cross sectionand a plurality of spaced apart holes, and with the locking devicecomprising a spring-biased pin insertable into one of the spaced apartholes.